Recently, a search service provider provides a service which retrieves keywords, inputted from a plurality of users during a predetermined period of time, and provides the retrieved keywords to a user as popular keywords. The service of providing popular keywords may readily predict a field which the plurality of users are interested in, based upon a season, a social matter, and the like. Due to the advantage, the service is in a commercial spotlight.
As an example, when the number of inputs with respect to a keyword ‘good pension’ has been significantly increased during the previous week, a search service operator may select the keyword ‘good pension’ as a popular keyword and provide the keyword ‘good pension’ to users.
However, although a user or a group of users, which are in a commercial relation in association with the keyword ‘good pension’, abusively inputs the keyword ‘good pension’, the search service operator may regard the keyword ‘good pension’ as a popular keyword without identifying if all of them are valid. Accordingly, the user or the group of users may acquire some benefits by maliciously utilizing the popular keyword service. The above-described example represented a case of abuse of the popular keyword service. The more the cases of abuse increases, the more users' distrust towards the popular keyword service may increase.
To solve the above-described problem, when the same keyword is continuously inputted using a single Internet Protocol (IP) address, an improved search service identifies the keyword as an abusively inputted keyword and ignores such abusive inputs in selecting popular keywords.
However, when a user or users abusively input the same keyword while changing the host address of the terminal it or they use, even the improved search service may not identify the invalidity of such inputs. As an example, when a group with malicious intent abusively inputs the same keyword using a plurality of terminals with IP addresses having different host addresses, the improved search service may not identify the invalidity.
As described above, the conventional search service may not effectively identify invalid inputs.
Accordingly, there is a need for a model of managing search mediation information, which can identify an IP address of a keyword input terminal as a particular class grade, and also identify terminals, abusively inputting the same keyword, by a network unit and thereby can more accurately determine invalidity of such inputs.